1. Field of the Invention
The present invention relates generally to jump ropes and more specifically to a jump rope construction which has a handle which permits a change in the force which is applied to the user's hands, arms and shoulders by the swinging rope.
2. Prior Art
The structure of exercise devices which are in the form of jump ropes has improved over the years from its beginning models, which featured a simple rope. More sophisticated structures were then provided wherein a simple handle was tied or otherwise crudely attached to each end of the rope. More recently, the structure has been improved wherein large wooden handles were staked by a metal plate, which defined a central opening through which a rope was held by a ball bearing assembly which fit within the wooden handle. One of the inherent problems in this type of design was the tendency of the rope to twist because of its connection between the rope and handle.
The simplified design was later improved to utilize a ball bearing assembly, but such assemblies were too expensive and sophisticated for the intended use. Its disassembly for repair or replacement purposes was impossible due to the particular connections used between the rope and handle. A subsequent improvement upon the devices taught in the prior art uses only a ball bearing assembly which defines as its center a rope opening through which the rope extends and is held by the stopping element. The ball bearing assembly includes the usual race and balls rotatably encased within a ball bearing housing.
One of the basic problems inherent in all of the devices taught by the prior art is the placement of the connection between the rope and the handle irrespective of whether a ball bearing assembly is used. Since the portion of the rope which extends from the handle must curve about the end of the handle in order to be placed in its proper position, any crimping or friction which is created between the rope ending and the handle will retard its proper use. In addition, the devices taught by the prior art fail to provide for means which would extend the effective distance between the portion of the handle which is held by the user and the interface between the handle and the rope. By providing for an effective extension of this distance, the force imposed by the moving rope on the hands, arms and shoulders of the user can be increased or decreased at will thereby enabling the user to adjust the ease or difficulty of the exercise.
A form of the present invention substantially resolves those problems inherent in the devices taught by the prior art by employing a handle which can be elongated or decreased in length. The change in the length of the handle will change the force imposed on the user's hands when the rope is in use. In addition, the placement of the connection between the rope and handle as well as the profile of the terminal coupling of the handle improves the ease with which the present invention can be used as well as increasing the efficiency of the total assembly. A preferred form of the present invention resolves the problems inherent in those devices taught by the prior art through the use of a resilient member which is disposed between the handle and the rope coupling and which flexes along its longitudinal axis. As the user rotates the rope at a higher rate of speed, the force which is imposed at the coupling between the rope and the handle will increase thereby creating a proportionally greater bending moment in the resilient member with a corresponding increase in the forces which are imposed upon the user's hands, arms and shoulders.